rrrdb: RDB built on top of RocksDB written in Rust

Under construction

See rust-rocksdb

How to Use

let rrrdb = RrrDB::new(path)
rrrdb.execute("test_db", "CREATE TABLE users (id integer, name varchar)").unwrap(); // should handle properly
rrrdb.execute("test_db", "INSERT INTO users VALUES (1, 'Alice')").unwrap();
rrrdb.execute("test_db", "INSERT INTO users VALUES (2, 'Bob')").unwrap();
let result = rrrdb.execute("test_db", "SELECT name FROM users WHERE id = 2").unwrap();
result == 
    OkDBResult::SelectResult(ResultSet::new(
        vec![
            Record::new(vec![
                FieldValue::Text("Bob".to_string()),
            ]),
        ],
        ResultMetadata::new(vec![
            FieldMetadata::new("name", "varchar")
        ])
    ))

Feature

SQL

Suported SQLs are like:

• CREATE TABLE users (id integer, name varchar)
• INSERT INTO users VALUES (1, 'Alice')
• SELECT * FROM users
• SELECT name FROM users WHERE id = 2

So, I'd say it's a tiny subset of SQL supported.

Supported Type

Basically, Int and String are supported. Boolean will be there soon, hopefully.

Design

Layered

• SQL layer
  • tokenize and parse given SQLs
• Planner
  • compile a given SQL into a Plan that represents how to fetch data from storage layer, which is RocksDB
• Executor
  • fetch data based on a given Plan
• Storage
  • can be considered RocksDB wrapper
  • get a record by a key
  • get a iterator on a ColumnFamily
  • put a record with a key

Storage Layer

Use RocksDB as a backend storage layer to persist actual data. RocksDB is a Key-Value store, and RrrDB is row-oriented database on top of RocksDB.

Using ColumnFamily of RocksDB to store:

• Metadata
  • ColumnFamily name: "metadata"
  • key: database name, value: database schema(JSON)
• Database
  • not in used
• Table
  • Stores records in a particular table
  • ColumnFamily name: <database_name>_<table_name>
  • key: primary key, value: record(JSON)

These are obviously too naive, but works.

License

Apache License 2.0